/Engine/Plugins/Experimental/Mutable/Source/CustomizableObject/Public/MuCO/ICustomizableObjectModule.h
These may only be called from the game thread
void RegisterExtension ( [TObjectPtr](API\Runtime\Core\Delegates\TObjectPtr)< const [UCustomizableObjectExtension](API\Plugins\CustomizableObject\MuCO\UCustomizableObjectExtension) > Extension )